That would be in the standby pin 1 of cp 458 right ? I am nearly certain I checked it, and have a small but positive number, something like .02 v dc if I recall. I have to check it again, but I know I got 5.5v @ pin 4 on cp458 Not 6v as I am supposed to. And got nothing @ pin 5 where I suposed to get 30v.
Cool.
Srinath.
Cool.
Srinath.
Hi,
Check the voltage at the fuse. I do not know what voltage should be but it is possible that it is 30 volts. If you read .02 volts at the base it is not right. That is zero volt and the relay will not pick up. Trace back the wire at connector pin 1 CP458 to see where it goes. No schematics does not t show the origin of the signal.
Check the voltage at the fuse. I do not know what voltage should be but it is possible that it is 30 volts. If you read .02 volts at the base it is not right. That is zero volt and the relay will not pick up. Trace back the wire at connector pin 1 CP458 to see where it goes. No schematics does not t show the origin of the signal.
Let me check it in a bit and post back, and yea .02v didn't sound right to me either. However that 30v @ pin 5 is from the big transformer I thought, hence it wasn't showing and was not a surprise to me.
I will put more schematics after checking, I didn't want to post a huge pic and spam the board. Thanks. So many things to check.
Cool.
Srinath.
I will put more schematics after checking, I didn't want to post a huge pic and spam the board. Thanks. So many things to check.
Cool.
Srinath.
Ok, the 10 ohm 30w resistor, r452 is perfect, right @ 10 ohm, all fuses test good on that board.
Assembly and testing follows.
Cool.
Srinath.
Assembly and testing follows.
Cool.
Srinath.
Pin 1 of cp458 is 0v, pin 2 is 2.82v dc.
What should be the pin 1 voltage, and its in standby, its not getting past that, so its got to have voltage in standby ?
Cool.
Srinath.
What should be the pin 1 voltage, and its in standby, its not getting past that, so its got to have voltage in standby ?
Cool.
Srinath.
That fuse is good, but see that comes form the power transformer. Which isn't engaging, how can that be, somehting is off, 1 sec, I'll check it anyway.
Cool.
Srinath.
Cool.
Srinath.
Hi,
You need to find what feed pin 1. It is the one that power up the transformer by closing the relays.
You need to find what feed pin 1. It is the one that power up the transformer by closing the relays.
OK time to scan in the other parts of the schematic. I will in a bit sir, thanks 1000000.
Cool.
Srinath.
Cool.
Srinath.
Its in the front board, I suspect that stupid sony chip has fried itself.
I'll post that schematic ina bit, but I am thinking of hotwiring the relays, I cant trouble shoot that chip, I dont think any one can.
BTW these relays dont do anything along the lines of "protection" modes do they ?
Cool.
Srinath.
I'll post that schematic ina bit, but I am thinking of hotwiring the relays, I cant trouble shoot that chip, I dont think any one can.
BTW these relays dont do anything along the lines of "protection" modes do they ?
Cool.
Srinath.
Check the voltage at the input of the transformer T451. You need to have AC voltage to be able to energize the relays.
t451 lights up the led in front, and gives me 5.5v etc, its working, it also gets warm.
I am thinking I'll wire the relays, I suspect the display board has a bad sony cx somehting chip.
Cool.
Srinath.
I am thinking I'll wire the relays, I suspect the display board has a bad sony cx somehting chip.
Cool.
Srinath.
I will try that tomorow, I have the amp apart now, all the 8 fuses in the main board have been checked and are all good. I will get back to it tomorow.
Cool.
Srinath.
Cool.
Srinath.
Hi,
No problem. When you have it together please check voltage at Pin 1,2,4 and write down the voltage.
No problem. When you have it together please check voltage at Pin 1,2,4 and write down the voltage.
On cp458 I have done that, 1 was 0 vdc, 2 was 2.82 vdc, and 4 was like 5.5 vdc. In standby mode. Wont power on to be able to get it in the on stage. Pin 5 was 0 as well, that 30v for it has to come from the main transformer.
That pin is fed by the front board where when you put on the tact switch. It needs that cxp82860 IC to send it voltage - or like close/open something that lets it get power. That isn't happening and I think that chip has got a glitch and isn't taking the command from the tact switch. I am sadly unable to reset it as well, and I cant remove and replace the chip either, it is too small and sort of made into the board.
Anyway I have been modifying the thing to let me pull different boards off without pulling the whole thing apart. Anyway I'll check those voltages and put it on here.
Cool.
Srinath.
That pin is fed by the front board where when you put on the tact switch. It needs that cxp82860 IC to send it voltage - or like close/open something that lets it get power. That isn't happening and I think that chip has got a glitch and isn't taking the command from the tact switch. I am sadly unable to reset it as well, and I cant remove and replace the chip either, it is too small and sort of made into the board.
Anyway I have been modifying the thing to let me pull different boards off without pulling the whole thing apart. Anyway I'll check those voltages and put it on here.
Cool.
Srinath.
Hi,
Okay then pin 2 need to be 3.5 volt or higher so the micro see it that the power it is on. the reading of 2.8 volt it is marginal and it is possible that the micro it is thinking the power it is down. I was looking for the specs of D458 UZ5V1 but I can not find it. I think it is a 5 volt diode but I do not know if it is true. I think the output should be 5 volts.
Okay then pin 2 need to be 3.5 volt or higher so the micro see it that the power it is on. the reading of 2.8 volt it is marginal and it is possible that the micro it is thinking the power it is down. I was looking for the specs of D458 UZ5V1 but I can not find it. I think it is a 5 volt diode but I do not know if it is true. I think the output should be 5 volts.
OK pin 2 voltage being low could mean I dont have a fully working T451 - transformer right ?
Or any of those diode bridge components ? or a burnt out D458UZ5V1 ? Is that your suspicion ?
man you are so cool, thanks so much for helping me out, that diode I can buy and swap it and see if it helps.
OK I should tell you and I am not sure how long it has been that way or if it was ever even powered up etc etc ... but R456 and c478 which are right next to each other on that board looked like they were in contact. No burn marks anywhere on the legs etc, and I pulled them away. I am not sure if it was something that happened when I was pulling other things, or if it was that way for a long time. But no burn marks for sure, not even any marks that indicated there was a current flow.
Cool.
Srinath.
Or any of those diode bridge components ? or a burnt out D458UZ5V1 ? Is that your suspicion ?
man you are so cool, thanks so much for helping me out, that diode I can buy and swap it and see if it helps.
OK I should tell you and I am not sure how long it has been that way or if it was ever even powered up etc etc ... but R456 and c478 which are right next to each other on that board looked like they were in contact. No burn marks anywhere on the legs etc, and I pulled them away. I am not sure if it was something that happened when I was pulling other things, or if it was that way for a long time. But no burn marks for sure, not even any marks that indicated there was a current flow.
Cool.
Srinath.
Hi,
That mean that pin 2 should be 5 volts. I looked back the threads but I do not see where you post the voltage at fuse F453. I need that voltage. The voltage to the micro it is pin 4 and it is reading 5.5 volts so the micro it is getting the right voltage it should be 5.5 volts. Now is to find why we have 2.8 volts at pin 2.
That mean that pin 2 should be 5 volts. I looked back the threads but I do not see where you post the voltage at fuse F453. I need that voltage. The voltage to the micro it is pin 4 and it is reading 5.5 volts so the micro it is getting the right voltage it should be 5.5 volts. Now is to find why we have 2.8 volts at pin 2.
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