Voltage check step fail (230VAC mains)

Depfa · 1266

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Offline Depfa

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on: December 03, 2017, 04:27:15 AM
Hello. I need some help with the final step of crack building - voltage checks.

Here is what i have done so far (Following "Crack_1-1_Manual_09-20-16.pdf"):


Page 29 - Power Transformer Secondary Test - 6.5V AC (OK), and 178v AC (OK) - Success.

Upon complete assembly as of page 45, double checked all joints, wirings etc, as suggested.

Then

Page 47 - Resistance Check - all resistances are as in manual. OK - Success.

My mains voltage is 230, wired transformer according to page 27 "IF your voltage is GREATER than 225V AC and LESS than 235V AC"
Page 49 reads :

Quote
The following voltages have been made with an AC mains voltage
of 120VAC, your voltages may vary up or down by about 10%:

Terminal Voltage (DC)

1. 50-100V
2. 170V
3. 0V
4. 170V
5. 50-100V

6. 0V
7. 90-115V
8. 0V
9. 90-115V
10.0V


But what i got is:

1. 180V
2. 388V
3. 0V
4. 388V
5. 178V

6. 0V
7. 238V
8. 0V
9. 241V
10.0V


Also, I noticed that upon immediate power ON, the voltage on terminal 1 was about 560 Volts and then slowly descended to stable 180 Volts

The page 49 manual says for 120VAC, but my is 230VAC, so seems like all voltages are proportionaly multiplied, but i dont think this is normal.


theory                  
120V   multpl.                     
-
100   0,83          
170   1,41                      
115   0,95          

measured   
230V   multpl.
-
180   0,78 -
388   1,68
241   1,04

???proportion is roughly the same, as for 120V above , only multiplied for 230V


I don't know what to do next
Please halp
« Last Edit: December 03, 2017, 08:06:08 AM by Depfa »



Offline Paul Birkeland

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Reply #1 on: December 03, 2017, 05:23:21 AM
The junction of the black wires on the headphone jack is an important joint that often times doesn't get all the way soldered, and it can create some strange readings like this.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Depfa

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Reply #2 on: December 03, 2017, 06:22:18 AM
Caucasian Blackplate i made few pictures. Please don't rant too much because i made place adjustements for few components. The wirings should be the same (checked several times, should be OK everywhere)

Maybe a quick look for mistakes, please?

Made a pic of phone jack for you, i think it is thouroughly soldered though.
---
Re-measured voltages from page 29 again
Power transformer pins 7-9 (green wires) = 6.5V
Power transformer pins 11-12 (berofe diode bridge) = 178V

this means i got wirings for 230V mains correctly?
and all further power consumptions (after bridge rectifier) should receive proper voltage, right?

---
Aaaand again re-measured control voltages.
Still the same (as in 1st post) = huge numbers: 180V, 389 V, 237V


Afraid to even switch it ON, not even talking about plugging some cans and try to play music.

Help, what to do.
« Last Edit: December 06, 2017, 10:43:11 PM by Depfa »



Offline Paul Birkeland

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Reply #3 on: December 03, 2017, 02:39:44 PM
I'm sorry, I can't provide any technical assistance when the kit is not built according to the instructions in the manual.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man