Bottlehead Forum
Bottlehead Kits => Eros Phono => Topic started by: bucketofguts on January 23, 2025, 02:26:32 PM
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1A 219
2B 218
OA 156
OB 215 ,.....?
OC 95
OD 83
OkA 97
Okb 83
OkC 1.47
Okd 2.61 ....?
-C4S has 2 leds not lit.
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Most issues like this come down to soldering issues on the front C4S board. I would reflow all the joints except the ones for the LEDs themselves.
https://www.youtube.com/watch?v=EN16Pi7pcfk (https://www.youtube.com/watch?v=EN16Pi7pcfk)
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Copy that and thnk you very much.
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After reflowing..................
A1 220
1B 218
OA 217
OB216
OC 212
OD212
OkA O
OkB 0
OkC 1.07
OkD 0.8
Lost two more leds.
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The 0V on OKA and OKB would tend to indicate wires not hooked up or some kind of broken connection with the 6922 socket.
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Will be checking. Thank you very much.
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Third time.......
1a 219
1B 218
OA 154
OB 216
OC 97
OD 84
OkA 98
OkB 83
OkC 1.9
OkD 2.70
All leds will work. Just not all eight at the same time. I changed out the 6922 valve for these last voltages. Two leds that did not light during first check came on the latest test leds near B! and OB test points not lit on latest test. They were on the first check.
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A fresh 6922 is a good idea, as faults in this circuit can damage that tube. You are getting closer but OB and IB are still stuck at about the same voltage, which would have me reheating the center leg of the MJE350 closest to OB.
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Side note. I have tries a few 6922s. all 4 leds will lite for a few seconds then the two leds Ii mentioned slowky go dim. will try your advice. Thank you for your time Sunday in the pm.
Salute,
b~
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Same issue with the DCV. Plug in and eight lights come on and a second or two two dim and go out. The four leds one the other board light and stay lit a few seconds later.
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You can try a fresh 2N2222 on the side that isn't working. I find somewhat often that soldering problems will take that part out once the amp is powered up, and fixing the solder still leaves a damaged transistor.
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I will touch base with E tomorrow via email on the part/ s. Thank you for keeping me in the loop. Oh yea it is Sat. not Sun.I still thank you very much!
Cheers,
b~
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I ordered a new C4S board and all new parts + an extra MJE350 and a 2N222 to put in my original board to try.. Hearing that the circuit can damage a 6922 hurts. I been putting Amperex American white lable PQ's in rotation each time I reflowed/ reheated. Have Mercy!
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New C4S board and all ne parts.
A1 219
1B 218
OA 159
OB 216
OC 154
OD 97
OKA 152
OKB 95
OKC 12.0
OKD 16.0
All leds are lit. the decimal point on the last two values are what I saw. The last two values my eyes may have been playing tricks. Black wite between the 174 uf resistors broke at some time during/after test it is fixed now.
Thank you for your time.
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VDC this morning: 2 times changed the 6922 for the first and the er86 for the second.
!A 220 233
!B 218 233
OA 135 135
OB 216 231
OC 115 116
0D 85 86
OKA 116 116
OKB 84 84
OKC 2.1 2,0
OKD 2.5 2.5
the latest results
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Your 6922 does not appear to be conducting, is it glowing?
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Yes sir
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I'd try a different 6922 first, just to rule that out.
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Will do. All mine have some hours on them. They were in an older preamp.
Thank you,
n~
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Alright I have plugged severial 6922s and their values are all the same values w/in a poin or two of the last # I posted.
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i guess i should add i can't see the ef86 glow..... the other two easy in a room full of daylight.
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After some reading I see the EF86 really does tot glow or get real warm. Knowing is 1/2 the battle.
.
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Any help? Standing by......................
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Not having an Eros, I can only suggest do you have 6.3 v on pins 4 and 5 with the tube plugged in? if not remove the tube and then check pin 4 and 5 and if you have 6.3b v without the tube plugged in then perhaps you might have a bad solder joint/ joints or a broken wire. Just one old mans opinion.
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I would also be extra, extra sure that the center legs of the MJE350 transistors are well soldered. They connect to the metal tab on the transistor itself, so they take some extra heat to solder properly.
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No joy same values. time for a cock tail!
thank you,
b~
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My Hakko 936 and my 907. Cardas quad core can get to 896 F. I have no issued heating the booard and componet. The solider joints are bright silver. I gave the center pins my best on the transistors on 2 boards now. Is there a way to test thoes in circuit. I am still in the fight.
much onliged.
b~
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When I receive Eros 2 kits with problems like this, it is almost always a solder issue on the front PC board, and sometimes the 6922 will be taken out in the process, and sometimes the 2N2222 transistors give up depending on what wasn't soldered. You can check transistors for shorts by setting your meter to beep for continuity and checking each pair of transistor legs for shorts.
Seeing 233V at IB on the front C4S board tells me that there's still an issue with the regulator board above the 12AU7 that needs to be dealt with.
The voltages you posted show that one half of the 6922 is not conducting (or being allowed to conduct), which could be a problem with the plate stopper resistors (they go to pins C1 and C6), a short on the C socket, a bad solder joint on the MJE350 feeding that half of the 6922, or possibly a shorted transistor that isn't allowing the current to be regulated (or a solder bridge on the bottom of the front C4S board will also do this).
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Thank you very much. I hve new hope!
b~
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I relinquish it to you Paul. I will speak with Queen E tomorrow. I am beyond condlence.
Kind regards,
b~
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Queen E says I need your OK to send back. Would you please fix my Eros.
Thank you,
Ben~
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I am going to send some pictures that might shed some light on the issue. It is damn hard to take pics of soldier joints. Still in the fight till it heads your way.
Cheers.
b~
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Going to order parts for the board C4S, and the second C4S. Really good pics prove to be harder than I thought w/ an Iphone. Still working.What parts for the other boards need replaced, worst case. I read your post of what you do when a EROS comes in fo repair many times. You refer to the front board. Please elaborate kind Sir.
Have a lovely weekend.
b~
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Typically the front C4S board on Eros kits I repair tends to be full of cold solder joints, and proper operation is restored by reflowing the joints on that board and occasionally I'll get a stubborn 2N2222 that has failed due to whatever the funky solder joints were doing to the kit to produce the failures.
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Thank you again. I would like to see you in action. May a video?
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i found a 10.7 K ohm 1072f on C7. I also transposed both of the WFL 103H 630V w? the WFL 303H 630 V.. What damaged could I have caused. All new parts on the way with a few MJE350 and 2N2222A's. I now own a NOS Hakko 808. My linux is not playing nice with icloud pics.Working on that.
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What's C7? The switching of the capacitors will only influence the EQ. You'd have to send me the whole kit as a repair when I have time if you want me to debug it.
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C7 Tube Socket PIN.
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Yeah, that's not great, and will cause some potential issues. It's probably a good idea to go over the rest of the resistor values to be sure they are all correct.
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Oh boy.........................
Thank you,
b~
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I would also mention that if the 90.9 ohm resistor that goes to pin 6 on the EF86 socket, or the 90.9 ohm resistor that goes to pin 1 or pin 6 on the 6DJ8 socket gets swapped with something else of a much higher resistance value, then you will fight endlessly to get things to work, but the problem will be the swapped resistor.
All of the 90.9 ohm resistors can be measured while the Eros is turned off and with the resistors soldered into the circuit.
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Thank you sir. Will do.. Have a great weekend!
b~