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Another project to tinker with . It had bad battery connections so I fixed that . I have 12v going to and away from the on-off switch , the push button battery check is getting 12v but no response when pushing button . The speaker looks fine but no sound at all from it . No corrosion at all on board -clean as a pin . I did notice the pcb has a lamp bulb on it but it does not light with switch on . I did check the lamp solder connections at the board and have 12v there . I don't suppose the board has a fuse anywhere ? I see no discoloration or any evidence of hot components on the pcb .
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The "lamp" should not light up. "Lamp" is a current regulator.
Is it the 2x pcb version?
You have test points on the pcb, you can easily check the voltages.
This one?
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Whichever version you have, the basic schematic for the 1265 covers all cases.
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This is the pcb file for the 1 pcb version.
I didn't draw it, so I can't guarantee the accuracy.
But it's a good enough outline to get by.
You need Sprint Layout software to open it.
The rest is very easy.
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Ok, the Sprint Layout file I posted is adequate.
It will help you.
Schematic too.Comment
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To save me some time can you tell me which components are likely to fail and cause the dead condition ? I have no formal electronics repair training so it's a bit hard for me if it gets too deep .Originally posted by ivconic View PostComment
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Many people don't do well with the Sprint Layout options, but it's very simple to trace the links, you use the "Test" option and you "light" the links easily.
That way you can keep track of all the links.
Find the power points (it's easiest on the opamp circuits) and you'll easily check if the voltage is getting to the chips and if it's correct.
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It is practically impossible to know for sure.Originally posted by ric44 View Post
The most correct answer is "ALL components!"
You cannot repair such a complex electronic circuit without effort and knowledge.
Ok, if you're lucky; everything is possible.
But as I said; you start "tracing" the voltage rails with a voltmeter.
And the best help to find your way is the Sprint Layout file I gave you.
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Well you ain't gonna believe this . I had cleaned the on-off - volume pot earlier with spray cleaner but neglected to clean the discrim pots . I thought what the heck might as well get them too while I'm at it . So I sprayed them down , gave them a few dozen turns , blew them out and air dried them for a bit then powered it back on . Nothing happened at first then all of the sudden she crackled a few times then came back to life . Woweeee lol !! Who would have thought a dirty pot could cause such failure ? Anyway it's working like a champ now and I did learn something here . Thanks ivconic for your help but it was not a bad component after all . Maybe others can learn from this . This is a great forum !Comment
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Well not quite as lucky as I had hoped . I installed new battery holders in it today and turned the machine back on............nothing . I checked and was getting good power to the board . On a hunch I left the switch on for a while . After an hour or so the detector came to life once again . Very odd behavior . I'm thinking it's a failing capacitor that finally builds up and retains enough voltage to complete the circuit and let the detector come on . The pcb only has two electrolytic capacitors on it so I think i'm gonna change them both out as the next step . Y'all let me know if you think I'm on the right track .Comment
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Quote: "I'm thinking it's a failing capacitor that finally builds up and retains enough voltage to complete the circuit and let the detector come on" .
Based on your previous 'form' , this is not the most obvious solution. There are only two aluminium electrolytic caps, both PSU decoupling, so unlikely to make a difference to performance in the way you describe ( warm-up issue ).
However, replacing them won't do any harm. You may also be unaware - there are many solid tantalum 'dipped bead' electrolytic caps on the board, mainly PSU decoupling, too. ( marked S.T on the schematic diagram ) These DO have a reliability issue, especially when used as power decoupling, the current surges they experience when used this way can lead to failures. Again , they may not be the cause of the warm-up problem, though, even if they are faulty/sub-par.
The +8 Volt power rail is one to check, if that shows any drift or incorrect voltage, it may point to problems in the discrete regulator circuit ( the part with the 2.5 Volt reference IC .. and tant caps )Comment
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Dear Mr. Yves Corniel,
I hope this message finds you well.
I am a hobbyist and outdoor treasure hunter who has long been deeply interested in your Pulse Star II metal detector. I am especially curious about its legendary deep detection performance.
I am writing to respectfully ask if you would be willing to share the schematic and PCB layout files for the Pulse Star II, including the complete Gerber files, source files, and SMT BOM/coordinate files. I would like to build one for myself as a DIY project.
I am a true enthusiast and would greatly appreciate your help. You can reach me at my email: [email protected]
Thank you so much for your time and consideration.
Best regards,Comment
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