No voltage at position 18 Mojotone 18watt tmb

Martinoils

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Paul G.

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There isn't supposed to be any voltage there. You need to check your OT connections since that's what you disturbed. Reflow the connections on pin 7 on each power tube. Sometimes a joint looks good but the wire isn't bonded to the pin.
 

Martinoils

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There isn't supposed to be any voltage there. You need to check your OT connections since that's what you disturbed. Reflow the connections on pin 7 on each power tube. Sometimes a joint looks good but the wire isn't bonded to the pin.
Thanks I’ll try that
Now I realize that 18 shouldn’t have voltage
 

Martinoils

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Hi, newbie builder, almost there but very low volume on two normal channels the master gain channel has more volume but maybe 60-70% of what a 15 watt should have .
Here are my voltage readings
1) 11.1
2) 324.6
3) 324.5
4) 0
5) 182.5
6) 281.1
7) 0
8) 27.6
9) 47.9
10) 45.1
11) 147.2
12) 147.8
13) 0.8
14) 0
15) 228.9
16) 2.4
17) 249.4
18) 0
19) 188.0
20) 142.0
21) 1.6
22) 0.8
Here’s the chart
AB823B15-DDAD-42D9-ADF6-E2CE40338526.jpeg

Here’s some photos of my build


997FE5C5-80F7-4BFF-BA74-EBEADF5962A5.jpeg
8D0854B1-077D-4EFA-8653-EEFF909AB67A.jpeg
8B33C4E7-81BA-40D3-9F87-835B61849438.jpeg
B211D01A-1FFB-482B-A1AB-276409BC9C7F.jpeg
16683691-C6F1-44DA-BEBB-3BEA83A91D43.jpeg
43D4BA5E-FA94-4226-9779-B48FDB86799A.jpeg

Any help I can get would be so appreciated!
Thanks for your help
 

Martinoils

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Thanks

thanks I will post them later with some photos as well
Don't stress. You'll get it resolved. Finish checking your voltages against that chart first.
Hi, reflowed pin 7 on all tubes
Much improved except that the volume is way off.
I posted a different thread under Mojotone 18watt tmb volume issues with voltage readings, chart and photos if you care to have a look.
5 & 6 seem to be way off.
Thanks for your help
 

Lynxtrap

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Do all your readings match the voltage chart? Did you double- and triple check all the wiring compared to the printed layout? That's work you need to do yourself, or confirm that you have already done.
 

Martinoils

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I have triple checked the wiring for sure and the voltage readings are off at position 5 and 6 compared to the voltage chart on the layout diagram I posted. I just finished re soldering all those connections with no change
Thanks
 

dan40

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Richmond Va
From reading the earlier post I see that you have reflowed pin 7 on the sockets. Many of your turrets also appear to be lacking solder which could lead to poor electrical contact. If you are having trouble getting good solder joints on the turrets, you may need a larger tip for your iron to help heat them properly.
 




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