Nintendo Entertainment System NES-CPU-06 Shield Insulation
The NES-CPU-06 revision of the front-loading NES-001 Nintendo Entertainment System mainboard can short against the console's metal shields. Nintendo's Service Department Bulletin 91129 says that circuit traces on this board, Nintendo part number 22667, may touch the upper or lower shield and cause a short circuit, and that electrical tape rated UL-94 V-0 must be applied to the board to prevent it. Nintendo told its servicers to make the change whether or not the console was under warranty.[1]
The bulletin lists four places where the board can touch a shield.[1]
| Location | Between | Board side in the drawing | Tape |
|---|---|---|---|
| 1 | The signal-side trace of C33 and the upper shield | Solder side | One 45 x 19 mm piece covering 1 and 2 |
| 2 | The two through holes beside DA3 and DA4 and the upper shield | Solder side | One 45 x 19 mm piece covering 1 and 2 |
| 3 | The four holes beside R3 and R4 and the lower shield | Component side | 10 x 19 mm |
| 4 | R9 and the lower shield | Component side | 10 x 19 mm |
The bulletin's text says tape goes on "three locations" but then lists four; its drawing shows three pieces of tape, one of which covers two locations.[1]
Symptoms
[edit | edit source]Nintendo's bulletin describes the risk as a short circuit between the board and a shield and does not list symptoms; it treats the tape as a modification for every NES-CPU-06 board serviced.[1] For diagnosing a console that does not work, see the Nintendo Entertainment System Troubleshooting Guide.
Safety
[edit | edit source]- Unplug the AC adapter before opening the console.
- The metal shields are very sharp; Nintendo recommends gloves.[2]
Tools and parts
[edit | edit source]- Electrical tape rated UL-94 V-0, cut to two pieces of 10 x 19 mm and one of 45 x 19 mm.[1]
- A Phillips screwdriver.[2]
Procedure
[edit | edit source]- Open the console and lift out the mainboard as described in steps 1 to 8 of Nintendo Entertainment System 72-Pin Connector Replacement#Disassembly, and separate it from the lower shield. The 72-pin connector can stay on the board.[2]
- Read the board revision printed on the board. Only the NES-CPU-06 is covered by the bulletin.[1][3]
- On the component side, find R3 and R4 and the four holes beside them (location 3), and R9 (location 4).[1]
- Stick a 10 x 19 mm piece of tape over location 3 and another over location 4, placed as in the bulletin's drawing.[1]
- On the solder side, find the signal-side trace of C33 (location 1) and the two through holes beside DA3 and DA4 (location 2).[1]
- Stick the 45 x 19 mm piece of tape over locations 1 and 2, placed as in the drawing.[1]
- Reassemble the console as described in Nintendo Entertainment System 72-Pin Connector Replacement#Reassembly. In the console the solder side faces the upper shield and the component side faces the lower shield, which is why locations 1 and 2 face the upper shield and 3 and 4 the lower.[1][3]
Testing
[edit | edit source]- Check that the shields seat fully without lifting the tape, then switch on and run a game.
Related pages
[edit | edit source]- Nintendo Entertainment System
- Nintendo Entertainment System Troubleshooting Guide
- Nintendo Entertainment System 72-Pin Connector Replacement
- Nintendo NES Service Bulletins
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Nintendo of America, Service Department Bulletin #91129, "Control Deck Repair: NES-CPU PCB (Part No. 22667) 06 Version Modification", one page, undated, with a drawing of both sides of the board. Hosted as File:Nintendo Service Bulletin 91129 NES-CPU-06 Shield Modification.pdf; see Nintendo NES Service Bulletins.
- ↑ 2.0 2.1 2.2 Nintendo of America, Authorized Service Center Manual, revision June 2002, chapter 4, disassembly procedure, pp. 26-28. Hosted as File:Nintendo Authorized Service Center Manual June 2002.pdf.
- ↑ 3.0 3.1 Mark Knibbs, Disabling the NES "Lockout Chip", rev. 0.4, 22 September 1997, steps 7 and 8: the board is turned over to bring the component side up once it is out of the case, and the revision is printed in white near the centre of the board.