Re: Sony PVM 2730QM - Power Supply
With R677 and PS654 installed but D654 removed:
on C654 I have 9mV
on D661 I have 0.28V and about 12V to the ground
on R654 I have 0V and about round 12V to the ground
on 140V live I have 0.3V
on 15V live I have 11.5V
on 8V live I have 0.01V...
sunomo1
Member
Last Activity: 03-02-2019, 06:45 AM
Joined: 12-28-2018
Location: Italy
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Re: Sony PVM 2730QM - Power Supply
No
0.14V
There is a buzzing sound, but not from D654....Last edited by sunomo1; 03-01-2019, 05:01 PM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
I've lifted D654 and R677 and I see no voltage on pin 22,23,24. But please take in account that my meter cannot measure less than 1mV.
It's very unlikely that this winding is half dead. I've previously swapped it with that of the working PSU.
Comparing the voltages between the two PSU I saw different values of the high voltage area. Also the original burnt resistors were R679 R683.
Btw by lifting D654 and R677 any cricket sound disappear. It's reasonable to think that disconnecting them something on the...Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Yes, +18V is +32V -18V is -27V. The problem is the 8V line...Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
I've checked again, and removed PS654 again. Now I've 2.5V on C654. On the 8V I've 0.6V. It's very unlikely that the transformer winding is bad, since it has been taken from the working unit.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
On the working PSU on pin 22 I've around 2 mV and on pin 23 I've around 1mV. However on the faulty PSU my meter is even unable to measure any voltage. So the fault should be on the high voltage side? Btw it's ok that the D601 outputs +-131V on the working PSU but +108V-104V on the faulty PSU? I don't think that it's faulty since it has been swapped...Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Hi everyone.
I've replaced D663 D664 and IC651 with brand new but I got 1V on the 8V line. Then I've put back the previous D663 D664 and IC651 but now I still have 1V on the 8V line.
15V line is stable to 15.7 and the 140V line is still unstable around 140V. Voltages to ground: On D654 I've A 6.5V K 0V. On D656 I've A 1V K 0V. Voltages around C659 is 0.63V and around C655 is 0.7V. Something has been burnt?Last edited by sunomo1; 02-22-2019, 05:57 AM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Taking D663 D664 and IC651 from the non working PSU and soldering them on the working PSU, the result is that the working PSU is able to turn the tube on but just for a few seconds. After then it turns off automatically. So these 3 parts were clearly defective and should be replaced. Going to buy them in the next few days.
Unfortunately the viceversa didn't help. Taking these 3 working parts from the working PSU and soldering them on the non working PSU, the result is that the non working PSU is still unable to turn the tube on. The...Last edited by sunomo1; 01-30-2019, 10:07 AM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Voltages to ground: On D654 I've A 6.5V K 0V. On D656 I've A 12.2V K 0V.
T605 transformer pin #22 connection ok with D654. Resistance from pin #22 of T605 to ground: 0.1 ohm...Last edited by sunomo1; 01-29-2019, 10:20 AM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
I've replaced (swapped from the working PSU) D654 and Q653 so they're ok. But around D654 A-K junction I've around 6V...Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
I've tested R652 R654 they are ok. I've swapped C658 D656 C663 C664 with those of the working PSU so they are ok.
Yes, but it wasn't open, just a lower value.
No, on IC651(8) without a load I have 6V on the bad PSU 12V on the working PSU......Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
When I try to turn on the monitor with the faulty PSU the voltage of the 140V line remains stable but the voltages of the 8V and 15V lines drop down to 3V and 2.6V respectively. Also the values of +18V -18V lines drop down to 17.5V and 16.9V respectively. On the other hand, using the working PSU no voltage drops down. But why is that?...Last edited by sunomo1; 01-28-2019, 12:31 PM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Yes
Yes
Yes replaced brand new...Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Ok I've now replaced IC602 (taken from the working board) and tuned RV651. Now I have 143.5-144V on the 140V line 12.1V on the 8V line 15.6V on the 15V line a 27.8V on the +18V line and -30.5V on the -18V line. Unfortunately the non working PSU is still unable to turn on the tube even the output voltages seem to be almost correct. Indeed the working PSU is able to turn on the tube, even having the IC602 swapped. So the reason is definitely not related to IC602, I suppose.Last edited by sunomo1; 01-28-2019, 09:07 AM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Should I replace IC602?Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Ok, I've now swapped the FC boards, placing the one from the working PSU, but the 140V output is still unstable ranging from 123V to 138V. I think that the problem must be found on the FA board.
Rotating RV651 I have 120V (stable) on the 140V line and 11.3V on the 8V line. I think that the correct voltages should be around 141.6V for the 140V line and 12.3V for the 8V line (it's what I get on the other twin monitor).Last edited by sunomo1; 01-28-2019, 05:27 AM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Very sorry, my mistake.
Voltages on IC602 (to the ground):
pin1 0 V
pin2 1.4V
pin4 96-97V
pin5 90-91V
pin6 98-99V
When I touch pin 4 with the multimeter I hear an additional strange buzz.
Voltages on D602:
anode-catode: 11.6V
anode-IC602 pin6: 3.7VLast edited by sunomo1; 01-25-2019, 04:13 PM.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
About IC602 voltages I have 103-104V on pin 1 and pin 9, 102-103V on pin 11 and 89-90V on pin 5. On the other side from pin 15 to pin 24 I have very low voltages, below 2V it's expected?
I've not yet tried to swap the FC board with the one from the working PSU because I don't want to burn it out. It should be safe to do that?Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
The fault has to be found on the Power Supply Board. I've a twin PSU and plugging it into this monitor the tube turns on correctly.Leave a comment:
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Re: Sony PVM 2730QM - Power Supply
Hi, thanks for your messages. I've replaced C620 C622 C652. I've checked C651 D660 and they're ok. On the +-18V lines I've 28.7 and 25.9 but it seems that they slowly increase. On the 8V line I've just 10.5 and on the 15V line I've 15.6. The 140V line is not stable and it still ranges from 123V to 138V. Very frustrating.Leave a comment:
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