Marshall Valvestate 265r repair

[Jazz P Bass]

4. TR13 B -1.13 C +1.02 E -.02 TR14 B -1.10 C 0.00 E 0.00 TR7 B -40.1 C -1.11 E -41.42 TR2 B -40.1 C -1.13 E -41.44

What do you see incorrect in this lineup?
Hint: there are a lot of zeros.
If you look at the schematic you will see that this cannot be true.
Either the reading was taken incorrectly or you have open copper traces.

[J M Fahey]

Let´s start by saying that the guy who draws Marshall schematics should be flogged in public.
This one looks specially made to confuse, rather than to help.
1) In the main PSU,(page 3), the main power rails (for which they don´t state voltages, ), coming out of BR1 and filtered by C7/C9, are called "+LT" and "-LT" , which would imply "Low Tension" , usually referred to the preamp supply.
The proper name, if anything, *should* be "+/- HT" or "+/- V".
2) *But* on the preamp power supply (page 2), the regulators ar fed from such rails , only *here* they are called "PSU +/- VE" (check connector CON3)
Well, you could figure it out if they stated voltages ... which they don´t.
You could also figure it out if they labelled that connector with the same name ... which they don´t. .They call it CON1 .
3) they call the "real LT rails" "+/- 15V" multiple times .... yet they factory state that 7812/7912 regulators are used.
Not a last minute , not enough inventory substitution, but from the very beginning.
4) the main power rails are around +/- 40V .
How do I know? Not because Marshall told me, that´s for sure.

Ok. I'm going to try to answer all questions I've been asked to the best of my ability.

These are my readings. No speakers connected.

1. I have 32 v ac coming off both halves of the transformer.

Good

2. The power rails, if I understand correctly, are at + and - 12 volts dc.

The *preamp* power rails are +/- 12V ; the *power amp* (or main) power rails are around +/- 40V.

3. TR15 B -1.14 v dc C -41.82 E -.03 TR16 B +1.02 v dc C +41.68 E -.02 TR17 B -1.11 v dc, C -41.79, E -.02 TR18 B +1.06 C +41.73 E 0.0 v

Hey !! Your amp is fine !! You have no DC at the emitters, which are the power amp outputs!!!

4. TR13 B -1.13 C +1.02 E -.02 TR14 B -1.10 C 0.00 E 0.00 TR7 B -40.1 C -1.11 E -41.42 TR2 B -40.1 C -1.13 E -41.44

TR13 E and TR15 B must be the same, yet you state -.02 and -1.14 żżż???
TR14 should have around 2V between C and E, yet it shows 0.00 on both points żżż???

5. R7 = 671r R15 = 21.75r

6. TR9 E .68 C -40.0 B .05 TR10 E .o7 C -40.0 C .05

TR9 E and TR10E must be the same, you show .68 and .07V żżż???

7. TR3 E .07 C -40.0 B .69 TR4 E .06 C -40 B .69 TR11 E 40.66 B 40.13 C .66 TR6 E 40.66 B 40.13 C .66

These look reasonable.
I am afraid that with all that parts pulling and resolderung you may have cracked tracks or pads, just where they join said tracks, bacause you are showing different voltages in points that are connected by a track.
Besides that, you show no DC voltage at the amp outputs, please recheck that.
Another Marshall maddening inconsistency: the left speaker output is labelled "leftout"; the right one "speaker".

[soundguruman]

There's something up w/ tr14

[leydenjar]

Just wanted to thank everybody who helped me. It turns out there were no failed components. I had to wire jumpers at a few points underneath the circuit board and this corrected the problem.

[J M Fahey]

Just wanted to thank everybody who helped me. It turns out there were no failed components. I had to wire jumpers at a few points underneath the circuit board and this corrected the problem.

Fine.
Congratulations.
It is consistent with:

I am afraid that with all that parts pulling and resolderung you may have cracked tracks or pads, just where they join said tracks, bacause you are showing different voltages in points that are connected by a track.

Pulling parts to check them outside often causes this.
Oh well.