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Author Topic: Terminal/pin values problem  (Read 594 times)

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Offline Alby0521

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Terminal/pin values problem
« on: June 23, 2018, 07:03:53 AM »
Hi All,

My Eros works but I have some strange readings and i believe i can have a problem with pin A4, C4 and B4.
I'd like any suggestion.
Below all the terminal, pins and volts checks (1st value is my reading and second is spec value):
1: 0/0
2: 85K/71K
3: 0/0
4: 74.7K/60K
5: 0/0
6: 460K/470K
7: 460K/470K
8: 0/0
9: 46.5K/39K
10: 46.5K/39K
11: 0/0
12: 74.8K/60K
13: 0/0
14: 85.2K/71K
15: 0/0
16: na/na
17: na/na
18: 0/0
19: 47K/47K
20 to 26: 0/0
27: 47K/47K
28: 0/0
29 and 30: na/na

Input:
Left (black): 46.9K/47K
right (red): 46.9K/47K

Output:
Left (black): 460K/470K
right (red): 460K/470K

A1:26.9K/27K
A2: 0/0
A3: climb/climb
A4: 0/*
A5: 0/0
A6: 74.7K/60K
A7: 0/0
A8: climb/*
A9: 47.1K/47K

B1:26.9K/27K
B2: 0/0
B3: climb/climb
B4: 0/*
B5: 0/0
B6: 74.7K/60K
B7: 0/0
B8: climb/*
B9: 47.1K/47K

C1:46.7K/39K
C2: 74.9K/60K
C3: climb/*
C4: 0/infinity
C5: 0/0
C6: 46.7K/ 39k
C7: 75K/60K
C8: climb/*
C9: 0/0

Volt Check
Right Channel:
KREG: 1
BREG: 102
OA: 159
IA: 220
BA: 0
OB: 100

Left Channel:
KREG: 1
BREG: 98
OA: 165
IA: 223
BA: 0
OB: 96

Is it possible that I fried the 1uF capacitor between C4 and C5? I think the other 2 capacitors connecting to terminal 8 are ok as I have good readings on terminal 8.

Thanks all in advance for any help.

Best


Offline Paul Birkeland

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Re: Terminal/pin values problem
« Reply #1 on: June 23, 2018, 07:14:17 AM »
Were the resistance checks done w/o the tubes in the sockets?

Since your voltages are OK, there's no cause for concern here.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Alby0521

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Re: Terminal/pin values problem
« Reply #2 on: June 23, 2018, 07:27:45 AM »
all the tubes were in the sockets when I took the readings. Any idea?

Offline Paul Birkeland

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Re: Terminal/pin values problem
« Reply #3 on: June 23, 2018, 07:35:26 AM »
Pins 4 and 5 on each of the forward 9 pin sockets are the heaters for the tubes.  Each tube's heater has pretty low resistance, and they are all in parallel, therefore pins 4 and 5 will look to be about shorted together, and pin 5 on each of those sockets is grounded.

If there was actually an issue, your voltages check would have failed.

For what it's worth, if we rewrote the Eros manual today, we would not have a resistance check for those pins.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Alby0521

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Re: Terminal/pin values problem
« Reply #4 on: June 23, 2018, 08:20:35 AM »
Ok thanks you very much.

Best