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#1 Posted : Sunday, June 26, 2011 10:52:07 AM(UTC)
toast

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Just done the duo mono BII with trident 2 days ago. First power on everything is fine, but the next morning after power on, only one of the BII lock on to signal (SPDIF), while the other one lock on intermediate. After some trouble shot, manage to found the culprit, it is the VDD_XO problem. Luckily I order an extra 3.3G trident and I got the BII Singing after replaced the faulty trident. I suspect the fault could be because of the trident not fully inserted into extended socket, I should have check all connection before power on. Is too late now.

Here is the reading of the faulty trident:
Both led light up
Output = 1.83v
R4 = 1.22v
Opamp pin 2 = 1.24v
Opamp pin 3 = 1.28v
R7 = 0.05v
R8 = 1.15v

What do you think is faulty? I want to repair this trident and use it as backup.
Russ White  
#2 Posted : Monday, June 27, 2011 6:14:22 AM(UTC)
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Is that test with Trident not connected to a load?
toast  
#3 Posted : Monday, June 27, 2011 6:39:00 AM(UTC)
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Yup, test with no load. I am afraid leaving it on board to test might harm the other components.
Russ White  
#4 Posted : Monday, June 27, 2011 10:19:22 AM(UTC)
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Right definitely don't do that.

First thing to do would just be to double check all solder joints.

Can you please give me the voltage across each resistor?
toast  
#5 Posted : Monday, June 27, 2011 2:04:20 PM(UTC)
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Hi Russ, here are there readings:

R7 = 0.05v
R8 = 1.15v
R9 = 0.75v
R4 = 1.22v
R5 = 0
R6 = 0
R1 = 0.88v
R2 = 0.84v
R3 = 1.05v

I have reheat all the joins I solder before (The pins and r4).

By the way I have use this trident a few days for testing to make sure everything work in stereo mode before shifting to duo mono.
Russ White  
#6 Posted : Monday, June 27, 2011 9:04:26 PM(UTC)
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Thanks, there is just one bit more I need. What is the voltage at pin 6 of the opamp to GND.

Also can you please read me the value marked on R3. OR take a good quality pic.

Edited by user Monday, June 27, 2011 9:08:02 PM(UTC)  | Reason: Not specified

toast  
#7 Posted : Tuesday, June 28, 2011 5:02:21 AM(UTC)
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Opamp pin6 to ground = 0.30v
R3 is written 104, picture attached.

Edited by user Tuesday, June 28, 2011 6:09:54 AM(UTC)  | Reason: Not specified

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trident VDD_XO.JPG (96kb) downloaded 472 time(s).

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Russ White  
#8 Posted : Tuesday, June 28, 2011 6:40:26 AM(UTC)
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Wow, ok that is strange.

That leads me to ask what is the voltage accross D1, D2 and C3.

The reason i ask is because the voltage across R3 is low.

Edited by user Tuesday, June 28, 2011 6:52:15 AM(UTC)  | Reason: Not specified

Russ White  
#9 Posted : Tuesday, June 28, 2011 6:43:07 AM(UTC)
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For reference voltage across R3 measures about 1.95V normally. You measured 1.05V Which is significantly low.

Edited by user Tuesday, June 28, 2011 6:43:50 AM(UTC)  | Reason: Not specified

toast  
#10 Posted : Tuesday, June 28, 2011 7:46:56 AM(UTC)
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Here is the measurement:
D2 = 1.92v
D1 = 1.93v
C3 = 1.92v
Russ White  
#11 Posted : Tuesday, June 28, 2011 9:53:59 AM(UTC)
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Well based on that I would say its a blown opamp and/or QP2. But some of the measurements like R3 seem odd.

Edited by user Tuesday, June 28, 2011 10:11:53 AM(UTC)  | Reason: Not specified

toast  
#12 Posted : Tuesday, June 28, 2011 4:44:41 PM(UTC)
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I will try to get both replace.
Thanks.

Edited by user Tuesday, June 28, 2011 4:45:18 PM(UTC)  | Reason: Not specified

toast  
#13 Posted : Tuesday, June 28, 2011 10:00:57 PM(UTC)
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Hi Russ,
I want to order the parts, can you let me know what is the code for QP2.
Thanks.
toast  
#14 Posted : Monday, July 4, 2011 9:59:15 PM(UTC)
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New opamp has arrived.

Try to remove the old opamp using desoldering wrick, not successful, heater works better. Solder in the new opamp, then test it with input of 5.00v and confirm got 3.23V output and R3 voltage across is 1,83v (higher input will put it back to 1.90v). Put it in BII and confirm it is working. Problem solved, thank you Russ for your support. Below pictures show it all.

Edited by user Tuesday, July 5, 2011 6:04:09 PM(UTC)  | Reason: Not specified

toast attached the following image(s):
trident_1.JPG (119kb) downloaded 386 time(s).
trident_2.JPG (82kb) downloaded 379 time(s).
trident_3.JPG (39kb) downloaded 376 time(s).
trident_4.JPG (21kb) downloaded 373 time(s).

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pellesmil  
#15 Posted : Tuesday, August 30, 2011 2:34:21 PM(UTC)
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Russ i have the same symptoms with my B2 the 1.2v trident is no good, it puts out near to 0 volt the measurements are mostly the same and 1 started to rule out the resistors, by comparing a working trident with the bad one i found the same values (apart from the r4 10ohm) i have apox 1.2v over r3 and when measuring the resistance it is steady 1.5Kohm the working trident measures about 100Kohm (i guess 104Kohm is iaw marking).

Should i try to take out the R3 and measure it or is the opamp causing a short in the circuit bringing it down to 1,5Kohm

Suggestions??

Edited by user Tuesday, August 30, 2011 2:36:20 PM(UTC)  | Reason: Not specified

Russ White  
#16 Posted : Tuesday, August 30, 2011 3:37:44 PM(UTC)
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R3 is different in 1.2V Trident from 3.3V trident.

This sort of problem is almost always a dead opamp due to over voltage.
pellesmil  
#17 Posted : Wednesday, August 31, 2011 7:22:04 AM(UTC)
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Russ White wrote:
R3 is different in 1.2V Trident from 3.3V trident.

This sort of problem is almost always a dead opamp due to over voltage.


Ok, thank you anyway, since im not equipped with adequate patience to perform smd soldering, i ordered a new 1,2v module instead.

P.
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