Yamaha VL70-M Troubleshooting

2.Add all the converted numbers.

3.Divide the total by 128 and note the remain- der.

4.Subtract the remainder from 128. The result is the checksum.

5.Convert the decimal checksum back to hexadecimal format using the above chart.

HEX DEC HEX DEC HEX DEC HEX DEC

40	64	50	80	60	96	70	112
41	65	51	81	61	97	71	113
42	66	52	82	62	98	72	114
43	67	53	83	63	99	73	115
44	68	54	84	64	100	74	116
45	69	55	85	65	101	75	117
46	70	56	86	66	102	76	118
47	71	57	87	67	103	77	119
48	72	58	88	68	104	78	120
49	73	59	89	69	105	79	121
4A	74	5A	90	6A	106	7A	122
4B	75	5B	91	6B	107	7B	123
4C	76	5C	92	6C	108	7C	124
4D	77	5D	93	6D	109	7D	125
4E	78	5E	94	6E	110	7E	126
4F	79	5F	95	6F	111	7F	127

Troubleshooting

The VL70-m is a very versatile tone generator with many features and functions that affect

operation. In many cases, what appears to be a fault with the VL70-m can actually be traced to an improperly set parameter or something as simple as a bad connection.

Here’s how to determine if the problem is internal (e.g. parameter settings) or external (e.g. connec- tions, amplifier, etc.):

●Listen via headphones. Plug a pair of head- phones into the VL70-m and play. If the headphone sound is OK, then the problem is most likely in the amplifier or mixer you are using, or the audio connection cables.

●Try adjusting all operational controllers — modulation wheels, foot controllers, etc. In some cases extreme controller settings can cause unexpected sound or pitch … or even no sound at all.

●Try selecting different voices. If the problem occurs only on one voice then the voice param- eters are most likely at fault. If the problem occurs on all voices then a utility parameter should be suspected.

The following are some common problems and probable causes:

Symptom

•No power.

Possible Causes

•Is the AC adaptor properly connected to both the VL70-m and an AC wall outlet (page 15)?

•If the AC apaptor is connected to a switched AC outlet on another piece of equipment (an amplifier, for example) is that devide switched on?

Appendix 107