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asr 10 boot problem

October 22 2011 at 5:01 AM
ccdouble  (no login)

 
my asr 10 has a boot problem when i start it up all the led lights up but no screen but when i press the cursor keys numbers show in the screen i downloaded the service manual read few forums and opened it tried reseating the ram re conecting the ribons making sure everything is seated proper. then put it on
same thing like described above left on for a while turned it off put it back on imediatly it works fine turned off on and off/on again to make sure it works loaded my os disk then loaded a floopy with bank and sounds worked and sounded great.
tried the sampling worked perfectly good too. i thought it was fixed so turned off next day back to same problem led lights on screen blank some numbers so i let it warm up 10 min aprox turned it off put back on the system works great and all the fuctions. i realized as long as the asr10 was warm up 10min on/off works no flaws. leave it off for an hour or more i get a blank screen and numbers until i let it warm up then it works fine. before it gets worse could this be power supply problem or could it be something else.

 
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AuthorReply
dave
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Re: asr 10 boot problem

October 30 2011, 3:52 PM 

cold solder joints.

dave

 
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Efectul
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ASR-10 boot problem

June 26 2013, 5:06 PM 

Hello,

I have the same problem...

The problem is that I live in the UK, not in the USA, so it's a little bit harder for me, as long as I didn't heard anything here about someone who fix this type of problems...

I bought from eBay.co.uk an Ensoniq ASR-10 in original box, used only twice about 10 years ago. Today I received it with the main cable which comes plugged and 2 floppy disks: One is AD-007 Stereo Drums and is original and the other one is Boot Disk OS 3.53 and is not original, it's a copy of original, probably...

When I plug the main cable and switch on the button from the back of the machine, all the small 16 lights (8red, 8 yellow) from the Instruments Sequence Tracks start to light up all together continuously with no stopping and the screen doesn't show me anything, as I saw on YouTube tutorials, but it seems to work proper when you press its buttons.

My questions are:

1. What should I do to make it usable?
2. What do I need to update it to 2013, as long as is from 1994?

Any information would me MORE than useful, as I don't know what to do and what to buy, to make it work!

Thank you very much for trying to help me, it means A LOT for me!!!

 
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Anonymous
(no login)

Re: ASR-10 boot problem

June 30 2013, 2:37 PM 

there is a guy in the UK the works on them, send me an email and I will forward his address to you.


dave
russell661@charter.net

 
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Anonymous
(no login)

Re: ASR-10 boot problem

July 1 2013, 8:33 AM 

As with my previous post one of the problems with this error is that it does not tell you where the issue lies. It may not be the RAM in your case but it is a cheap way to do a test of the problem.

This error occurs when communication between boards is not working correctly. It could be the RAM as with mine or it could simply be a blown fuse which supplies one of the boards from the PSU. It could also be a more expensive problem where one of the boards needs replacing or fixing.

I would definitely suggest the RAM solution first by trying to swap them out. If you don't have the manual then there are pdfs online which contain the full installation instructions with jumper settings. Next try the fuses because a replacment fuse will cost pennies. It's awkward to get to as you will have to remove the main board to get to it but they are easy to replace.

Beyond that I'm afraid I can't be much more help. With the exception of Syntaur and the parts they try to keep. I also saw some spare boards on ebay.co.uk a few weeks ago.


 
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Se|\|se-A
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Fixed!!!

September 24 2017, 6:48 PM 

I had the same problem. It would boot and show the instrument leds lit up. But it wouldn't load. Pressing buttons gave me strange characters going across the screen.

Turned out that the jumper settings were wrong. I reseated the ram chips and checked the jumper settings to what the service manual recommended.

I now have one of my 2 asr 10's working again!

 
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Anonymous
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Re: asr 10 boot problem

July 1 2013, 7:55 AM 

Really old post. If this still applies I would still go with the RAM being the issue before anything. I bought one which was upgraded and it was doing this. One day working next day not. Same issue with the common no boot, no screen / weird digits on the screen when pressing buttons.

The problem would temporarily go away when I opened the unit and removed and re-seated the RAM. I decided to check it out and dropped the RAM down to half by only keeping 2 modules in place (also had to change the jumper settings)and ran like this for a while. When I was satisfied that there were no issues I simply swapped one of the RAM modules out till I found the fault.

Upon further investigation it seems that the previous user had installed the incorrect type of RAM according to the user manual and one of them was misbehaving within the ASR causing unpredictable behaviour. I ordered some new ones off ebay and installed the correct types and voila! My ASR 10 has never done it since.

 
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jhulk
(Login jhulk)

Re: asr 10 boot problem

July 22 2013, 5:15 PM 

this is a diagnostic mode

this tells you that there is a communication error

between the screen board the digital board and the keyboard or kpc emulator on racks

it means you have lost a communication link

now if all leds stay on and the screen is blank then you are in this diagnostic mode

you have to press a key sequence that puts out numbers on the screen if the numbers just stay to the left but change means there a problem with the 20 pin connector from the digital board and the keyboard

if the numbers track the screen as they go along until a key press is home curser and starts again from the beginning then you press some more once all the key routine has been pressed

you switch of and then you switch back on again it will then be out of the diagnostic routine ad you should get the boot screen

if not then its a bad communication error and needs to be looked into

 
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Anonymous
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Re: asr 10 boot problem

July 23 2013, 10:55 PM 

jhulk

hello
you seem to have tons of knowledge about the ensoniq family.

question if I may....

"if not then its a bad communication error and needs to be looked into"

so what would you recommend after that statement?
something is wrong with the main PCB. I am trying to figure out what.

I have the proper voltages on the cap. I measured voltages against a working main PCB and that is how I know that this one is bad. are there some common things to look at when these Main PCB fail.

lastly, do you have or have you ever seen the schematic to the asr10? I was told that they don't exist but, I have a main PCB that has been heavily modified and you can cut vias and rewire circuits without a schematic....
share what you know, thanks
d

 
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jhulk synth and sampler repair
(Login jhulk)

Re: asr 10 boot problem

July 24 2013, 1:36 AM 

they never released the schematics for the asr10

but a lot of it is reused circuits

the screen board for keyboard and rack use the same controls as an eps16+

there are a few variations but not much the audio board apart from using a different pcm input dac for the output section they still use the same 2,s compliment dac and the same tl072 opamp circuits made up of a lowpass reconstruction filter for the stepped dac output wave and the unbalanced line level opamp for the output

the expander boards are identicle to the eps16+ expander boards and are included in the racks

the psu in the asr10 copy circuits from the topology of the eps16+ notibly the -125vac for the vfd control for bringing on the neon lights this voltage gets sent to the vfd control chip which has a matrix row and column for placing words and text onto the screen

the buttons on the screen board act as pulldown circuits 5v by pushing a button momentarily it takes it down to zero volt causing a short this short is the measure by the matrix and it see,s the row and column via its scanner cpu and the digital input from the processor sends the correct words from the look up table for that switched matrix location

on the asr10 ensoniq decided to keep the analog separate from all digital signals

so they incorporated a signal transformer so that the big noisey transformer for the screen and digital board and the 5v circuits for the screen board and the floppy drive

did not enter the audio chain it takes its ac voltage direct from mains from the same connection as the input wires of the big transformer it goes through some noise suppression caps which stops noise from the mains incomer then it goes through the signal transformer its a dual 110 pri windings and why it can be linked for 240v by making the 2 110v in series and why there is only 1 psu pcb

the secondary windings comes out at 36-38v or 17v-19v ac this goes through a bridge rectifier circuit via 4 glass rectifier diodes these are very good quality and are nice and large even bigger for the digital circuits it then goes through some ripple filter caps the 3 smaller ones then the 0v -17-19v and the +17-19v then go to the analog board where there are power regulators on board just for the analog board and its ampage requirement

the digital board has its own power regs and the ram section gets 2 power regulators for constant 5vdc 1 for each dual section of ram

now you say the voltages are wrong on your digital board where are you measuring at what points check for cold solder joints on the power regs for ram as they are connected to the heat sink if to much movement happen the legs can crack and you can get a loss of connection

the other power regs are on board the pcb and have heat shrink over then this is because the backing metal part is live when powered on

if you can tell me where your measuring your voltages i can go through were the breakages could happen and what could be bringing down the voltage most caps in those situations are just bypass they keep a constant voltage there if you removed it the circuit would still work but if the voltage fell below the minimum you would not have a back the cap charges and dist-charges so that the 5volts going in is kept at 5v or what ever voltage its doing

its so you dont get pumping

and the reason on car power amps they use big surge capacitors to reduce voltage and am-page bloat

 
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Anonymous
(no login)

Re: asr 10 boot problem

July 25 2013, 1:32 AM 

1.now you say the voltages are wrong on your digital board where are you measuring at what points check for cold solder joints on the power regs for ram as they are connected to the heat sink if to much movement happen the legs can crack and you can get a loss of connection

2. the other power regs are on board the pcb and have heat shrink over then this is because the backing metal part is live when powered on

3. if you can tell me where your measuring your voltages i can go through were the breakages could happen and what could be bringing down the voltage most caps in those situations are just bypass they keep a constant voltage there if you removed it the circuit would still work but if the voltage fell below the minimum you would not have a back the cap charges and dist-charges so that the 5volts going in is kept at 5v or what ever voltage its doing

its so you dont get pumping

and the reason on car power amps they use big surge capacitors to reduce voltage and am-page bloat

thanks jhulk for the insight.



first off. This asr10 was working 100%. it has sat up against a wall for the past 2 plus years.
I was going to do some testing on a bad analog board so this is why I grabbed this unit.
I powered her up and that's when the trouble showed itself.
My first thought after I verified that it was the digital board was that maybe a cap had dried out, after all the unit it 20yrs old.
I powered the unit up and checked all of the VR and the ferrot beads ,transistors as well as all of the caps.
I did this with a working digital board first , documented all of the voltages then I proceeded to check these locations with the bad digital board. all VR ,FB , transistors and caps show proper voltage . then I thought that maybe a resistor was shorted or open. I checked voltage drops across resistors in the J1 display connector location. that's where I found the issue. R1,R6,R18and R8 show wrong voltages during operation on the bad digital board. I then did a continuity test to see where these resistor supplies or retrieve their voltages from. I traced them back to U1, U2, and U4. I then verified via the working digital board that all voltages were present on there IC pins and they were. I also verified that the resistance was correct on R1 and R6, it was. I didn't trace R8 and R18 yet as I though that the first 2 would be enough but I may need to get that info too.
So I wanted to know if you have ever ran across IC's being the issue before I replace them. I just want to be sure.

so the voltages across the working digital board's R1 is 5v and 2.5v. R6 is similar. The bad digital board has R1 4.9v and .003v. as I said, both of these location pin out the U1,u2 and U4. I also measured the power up voltage at R1 and it goes to 5v instantaneous then fall to .003v. when I did this to the good digital board it didn't got to 5v, just the 2.5v that it read to whole time.

I hope that this is enough info to start.
as for cold solder joints, that is one of the first things I look for, all is good there. I also made sure to check all of the voltage and gnd pins on the IC's and not just the cap location. all is good there too.

thanks again
d

 
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jhulk synth and sampler repair
(Login jhulk)

Re: asr 10 boot problem

July 25 2013, 5:41 AM 

u2 is a static ram chip 16k 2kx8bits

the other 2 chips are logic chips that interface with the os rom chips

the u5 is a rom chip with code that gets read into the static ram and the os rom

thats the start up boot routine rom the code for the flash start up screen and the floppy access to boot from floppy or scsi if connected

the os rom chips are used when the os code is loaded from floppy into memory

boot rom on this board i have here is v1.1 6457

the logic chips are pennies few quid max

that make of static ram might be a problem

that chip was used in data and telephone circuits

the chip is a t6116 sa25tp delta

see if you can find one first




 
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jhulk synth and sampler repair
(Login jhulk)

Re: asr 10 boot problem

July 25 2013, 6:16 AM 

also if you can try and get military grade parts there better as they work to a higher specification and heat range -55oc to 125oc

commercial grade is 0oc to 70oc

which is what most parts are in ensoniqs if changing caps in psu filer circuits always buy the military grade high spec they only cost a little more and life is much longer

and dont sufer the heat problems like the lower temp grade stuff

 
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Anonymous
(no login)

Re: asr 10 boot problem

July 26 2013, 1:30 PM 

thanks for the insight and we'll do.


d

 
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