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Pioneer VSX-3300 Problem

O

ONEe

Member
Pioneer VSX-3300 Problem(repair help)

Few days ago i bought this pioneer VSX-3300, cost me 2€ only. Anyway i tested it with mains and it worked about few minutes then protection relay starts to on/off rapidly. Yesterday i tested it again and now relay is not clicking so now i tested it with my lp player and one speaker, but no sound(all speaker jacks). Only screen turns on nicely.

What might be broken then? Does anybody have schematic for this?

Pictures->https://www.dropbox.com/sh/zb1koyr320liyjm/ubqhF59M01
 
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Today protection relay started clicking again.

Also tested output transistors.
Code: 
Q1 and Q2 2SC3281     | Q3 and Q4 2SA1302 
B-C 0,48v             B-C >2v loading capacitor?
C-B 0,65v             C-B 0,48v
B-E 0,157v            B-E 0,157v
E-B 0,157v            E-B 0,157v
C-E 0,76v             C-E 0,53v
E-C 0,5v              E-C >2v loading capacitor?
 
There is a printed manual on eBay - supposed to be original, 31 pages, doesn't say how many blanks... Other sources except stereomanuals.com are dry...

Either would be a good investment, Rick at stereomanuals.com's manual is listed as 44 pages of which 18 are blank makes 26, some stuff is listed as > on microfiche.

Or you could buy one of Rick's excellent reproductions - I have never regretted buying any of Rick's manuals. Maybe we won't need what's on fiche...

as far as the unit, try re-seating every connector by unplugging and replugging them, say twice... Then look CAREFULLY for cracked solder joints IF the symptoms continue.
 
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There are only 3 connectors but they are fine now. Also didn't noticed any cracked joints yet. Tried if it works after that but still no sound and no relay clicking. Then I measured some voltages at the main board, only place where i can measure voltages right now.
5v rail=4,94v
12v rail=12,18v
-12v rail=-12,68v
There ware R L pins too but they ware 0V.

Added picture from back of the main board.
https://www.dropbox.com/sh/sh5o3qp6b6w894m/3cPydcPtLj
 
most of those readings were unclear, and doing my best to decypher them:

Q1 and Q2 2SC3281 | Q3 and Q4 2SA1302
B-C 0,48v B-C >2v loading capacitor?
C-B 0,65v C-B 0,48v
B-E 0,157v B-E 0,157v
E-B 0,157v E-B 0,157v
C-E 0,76v C-E 0,53v
E-C 0,5v E-C >2v loading capacitor?

all are under 1.0 volts
were these in circuit?
was the circuit powered on?
what mode was the meter set to, making these readings? Ohms? diode test?

better yet, starting from scratch:

this would be a readable reporting format: +1.007V , -0.675V

the voltages are measured with the black lead of the dmm connected to a bare metal chassis ground.(unless explicitly instructed to do otherwise)

probe with the red leads, insulate all but the tiniest portion of the tip of the probe. Usually set on the voltage range. If your meter does not auto range, you must select the maximum voltage expected (like a 200v range)

read the emitter base and collector voltages of q1, q2, q3 and q4 and report each one separately. q1 and q2 readings cannot be combined. Neither can q3 and q4 readings.
 
That was diode test, and circuit was not powered and they ware in circuit, i combined them because readings ware almost same. But i measure them again. Do you want readings when powered on?
 
Do you want voltages measured between transistor legs?
Here is the voltages to ground. Also speaker switchs ware off
Q1
B +0.444v
C +53.7v
E -0.071V
Q3
B -0.579V
C -53.5v
E -0.071V
Q4
B -0.552v
C -53.5v
E -0.045v
Q2
B +0.466v
C +53.7v
E -0.044v
 
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Those are excellent readings (correctly done and posted, as well as signifying electronic health) so far, I can tell a lot from them. And while the idle current may be a bit higher on one channel, no problems are yet announcing themselves.

Which is good, simplifies the task.

Voltages between transistor leads are not the norm, plus when they are in circuit, and the unit is turned off, and the ohms or diode tests are used, the circuit interferes, as your first set of readings illustrated. Either the transistors come out for test or the power turns on and the voltage range on the meter is used.

That said, SOME gross faults, like massive short circuits will show up, but they are the rarer cases, usually found when checking output transistors.

So right now, with the power on, there is no relay click or sound, correct?

Now you need to find Q604(2sc1845, probably ecb) and Q606(2sa1115, probably ecb) and read the voltages on all three leads each. Go left to right on the leads with the transistor's lettering facing you, since we have minimal information. They are next to the Tape2/dat jack and Q606 is about an inch inboard from the J5 connector (between a wire jumper and R620 brown black yellow gold) while Q604 is right at J5's corner.

Q606 has to be mis-marked on the schematic, the drawing and circuit show a pnp transistor, while an NPN number is named, so I took a guess as to where the mistake is made, and you must figure out what the number on the transistor in the Q606 position really is from it's markings....
 
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Nice to know that those large transistors are ok. When i power up the amplifier there is one relay click but that is standby relay i think, in schematic RY 502 probably. After that no relay clicks and still no sound.
 
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Q604 and Q606 are near the power supply and bottom plate that comes off doesn't go that far so i must think now how i can measure them. They are near that regulator in one of the pictures.
 
I will only be on the forum randomly today for short time periods. I too have dragons to slay.
 
This may take a while, took off that back connector plate, found many cracked solder joints. Hopefully this will fix this amplifier.
 
There is one way to measure those transistors, but this needs that i remove that huge heat sink. This means that when powered on output transistors doesn't have heat sink, is this ok?
 
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Q604 is 2sc1845 and Q606 i dont know, markings are 115 first line and under that 9XF. Strange thing is that q604 in datasheet legs are marked left to right ecb but in pcb 3rd leg is marked E, might be just wrongly printed to pcb. You can see that in the picture, no E on the left and 1159XF has E on the left. More pictures

I tested Q604 with diode test and no power. And that marked E leg is grounded.

Anyway i test that Q604 and when we know what that Q606 is, then i will test that.

Probably leg markings are wrong here but anyway, order is same as in the datasheet
E +0,666v
C -0,007V
B +0,0018V

When this thing starts to work should there be two relay clicks? Now when i press power on there is immediately one relay click but should that other relay click too?
 
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