Tecnico

WEI-YA Model 1820HR/PROMAX C1016 Repair Guide

GENERAL INFORMATION:
This is a “universal” replacement chassis for 19 - 20 inch tubes that can be used to
replace chassis from these competingmanufacturers that use a high impedance (30 to 56
ohms) on the yoke vertical section: Nintendo Sanyo, Kortek, Eygo 1H, Promax C5100,
and Nanao. This chassis requires operation with an isolationtransformer. Standard
resolution (CGA) mode. To identify this chassis, remove the screws around the outer
perimeter of the black plastic circuit board frame and carefully lift the circuit board out of
it.Flip the board over and on the foil side next to the fuse holder clips should be
“1820HR” silkscreened in the foil. The manufacturing date should also be silkscreened
directly below that.
The neckboard is marked “428H CRT” on the foil side. The remote adjustment board is
marked “620 RC”.
The monitor width range can be changed by means of a red jumper wire and two pins
labeled “W” (wider) and“N” (narrower). Move the jumper with the power off. Then you
can power on and adjust the width coil to the desired size picture width.
Components NOT installed on this board: T302, R615, R616,C408, C411, C908, R422.
Jumpers NOT installed on this board: J20, J31, J33, J37, J38, J48.
Jumpers installed on main board: J1 through J19, J21 through J30, J32, J34 through J36,
J39 through J47, J49is installed in place of diode D807.
Please note that when replacing the electrolytic capacitors, the polarity markings are only
on the component side. The shaded area of the circle indicates thePOSITIVE side.
Transistor Q302 is type 2SC4742 and is the horizontal output. Transistor Q903 is type
2SD1402 and is the B+ regulator.
Fuse F1 is an AGC 6 (6 amp normal blow). Fuse F2 is an AGC 2 (2amp normal blow).
Flyback markings:
M1820H-C20X04
ETF-40L310AYT
T453
30-1

CAPKIT LISTING:
C701
C702
C703
C704

1 uf @ 50 volts
1 uf @ 50 volts
100 uf @ 16 volts
47 uf @ 25 volts
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