Service manuals, schematics, eproms for electrical technicians

HEATHKIT HDP-21A MICROPHONE SCH

AUDIO - SERVICE MANUAL
Type: (ZIP)
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Category
AUDIO
SERVICE MANUAL
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  • Also known:
    HEATHKIT HDP-21A MICROPHONE HDP21A HDP 21 21A
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  • See related repair forum topics below. May be help you to repair.
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Relevant AUDIO forum topics:
BASF D-6310 HIFI RC Rádiótuner javítás
Segítséget kérek.
Kaptam egy ilyen rádiótunert.
BASF D-6310 HIFI RC
Bekapcsoláskor a hálózati nyomógomb melletti led piros zöld váltás megvan ha nyomkodom a hálózati kapcsolót.
Semmi egyéb reakció nincs, nincs kijelzés.
Belül van egy relé ami meghúzna, de nem teszi.
Van egy havernak ilyen, ő jó messze lakik tőlem, elektromossághoz nem ért.
Nem tud segíteni sajnos.
Kapcsolási rajz kellene hozzá, nem egyszerű a tápegység része.
Ezt a kapcsolási rajz kérést rögzítettem a kérések között is.
Erről van szó.
https://youtu.be/yOEwbAwUT7I
Tud valaki segíteni nekem?
Üdv minden fórumozónak.
Trio-Kenwood: KR-3010 [Radio] S.N.962845 / Does not work, the final floor and prefinal floor defect with many burned component/

I greet you! I would need the scheme of this "vintage" amplifier that needs to be "restored". The problem is that in the prefinal and final floor I have many "fried" resistors well, their value cannot be identified.I replaced the defective transistors: 2SC1509, 2SA777,2SB690 and 2SD 796 (each 2 pcs.) and the electrolytic capacitors adjacent to them. I could not go further because of the carbonized resistors that I do not know their value (I can only guess that they are values small, in the order of ohms). The schematic diagram I downloaded, from the address received by the kindness of a colleague is not complete - it is a single page (missing Q29-Q30-Q31-Q3 and resistors R115-R116-R117-R118 which are completely carbonized, at other resistors I could see their value).Thanks in advance!
Finally, I found the missing part

If stuck in the repair and you ask questions, please do it as follows: - Details: Give the exact model number of your device and the chassis ID (if there is). - If possible, please attach pictures of the appliance. - Anamnesis: Write down the exact symptom. If hard to describe the symptom, it is difficult to verbally defined clearly, attach pictures or sound of the phenomenon! - Tell what was you have done so far: search contact error, which parts has examined or changed yet, etc... The incorrectly named topic suspended and will be deleted after 48 hours! Suspended state while others are not able to comment until you correct the address. Subsequent repair of the defective title (within 48 hours) by clicking on the "Edit" tab can be carried out.

Turntable Victor/JVC TT-71
Given:

Victor TT-71, neon lamp does not light, speed is lower than normal.  This is subsequent some short circuit the owner does inside the device.  No further details.

I found out the VICTOR QL7 have the same motor driver amd I downloaded the service manual that I attached here in case this manual is not already uploaded.

Looking at the diagrams I found out that at TP3 (same with pin5 of IC803) instead if that rectangular signal, I have nothing but 5VDC and a negative or positive short spike whenever I'm starting or stopping the motor and 
Under the circumstances I suspect IC803 is defective.  The bad thing, IC803 is NPC SC8043.  Also I wonder if the crystal is fine (except that I wonder what can be wrong with a crystal after some short circuit).

Does anybody have any more suggestion?

Also, where can NPC SC4043 be sourced?  Also, a crystal 9.054MHz?

Thanks in advance,
Corneliu
GOLDSTAR FFH-313L HI-FI lézerfej csere után pattog
Sziasztok 

A fent említett hi-fi-be cseréltem lézerfejet, mert nem olvasott a régi.
Az új olvas, lejátszik, de a hang alatt halk pattogások hallhatók, mint amikor karcos,  sercegős egy hanglemez . (statikus töltés kizárva) 
Lehet D/A átalakító hibás lenne bezajosodott ?

Képeket tettem fel, hátha van valakinek... 
Köszi
Üdv
Szabi
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